期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2015
卷号：112
期号：32
页码：10002-10007
DOI：10.1073/pnas.1502159112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceWe have developed a contrast screening strategy of systematic evolution of ligand exponential enrichment to isolate an RNA aptamer targeting specifically to p53R175H. This RNA aptamer partially rescued p53R175H in both cell cultures and tumor xenografts. p53 mutations are found in more than half of human cancers, and it is of biomedical significance to be able to isolate an RNA aptamer against a p53 mutation. This may also be the first report about an RNA aptamer specific to a mutant protein with a single amino acid change, and a plethora of human diseases are actually caused by single amino acid mutation. Thus, we present here a proof-of-concept study in isolating a specific and physiologically functional RNA aptamer against mutant protein with single amino acid substitution. p53, known as a tumor suppressor, is a DNA binding protein that regulates cell cycle, activates DNA repair proteins, and triggers apoptosis in multicellular animals. More than 50% of human cancers contain a mutation or deletion of the p53 gene, and p53R175 is one of the hot spots of p53 mutation. Nucleic acid aptamers are short single-stranded oligonucleotides that are able to bind various targets, and they are typically isolated from an experimental procedure called systematic evolution of ligand exponential enrichment (SELEX). Using a previously unidentified strategy of contrast screening with SELEX, we have isolated an RNA aptamer targeting p53R175H. This RNA aptamer (p53R175H-APT) has a significantly stronger affinity to p53R175H than to the wild-type p53 in both in vitro and in vivo assays. p53R175H-APT decreased the growth rate, weakened the migration capability, and triggered apoptosis in human lung cancer cells harboring p53R175H. Further analysis actually indicated that p53R175H-APT might partially rescue or correct the p53R175H to function more like the wild-type p53. In situ injections of p53R175H-APT to the tumor xenografts confirmed the effects of this RNA aptamer on p53R175H mutation in mice.
